我有代码需要做这样的事情
有一个类列表，每个类都有一些方法（比如说 execute()）。我需要在每个类上调用该方法，并且每次调用都有一个固定的 timeOut。现在，该类的其中一个执行方法写得不好，导致超时，导致 jvm 不退出。我正在这样上课。
java ExecutorServiceTest execute TestClass1 TestClass2 TestClass3
为什么jvm在代码执行完成后不退出？
我得到以下输出
In class 1
In Class 2
java.util.concurrent.TimeoutException
at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at ExecutorServiceTest.main(ExecutorServiceTest.java:78)
java.util.concurrent.TimeoutException
at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
第二类的执行超时，之后第三类的执行也超时。为什么第三类的执行超时？
执行完成后jvm不退出。是什么原因？还有为什么TestClass3执行超时？
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
class Task implements Callable<String> {
Object instance;
Method m;
Object[] input;
Task(Object instance, Method m, Object[] input) {
this.instance = instance;
this.m = m;
this.input = input;
}
public String call() {
String s = "initial";
try {
m.invoke(instance, input);
}
catch (RuntimeException e) {
}
catch (Exception e) {
}
finally {
}
return s;
}
}
public class ExecutorServiceTest {
public static void main(String[] args) {
String methodName = args[0];
String className;
List<Object> instanceList = new ArrayList<Object>();
for (int i=1;i<args.length;i++) {
className = args[i];
Object o = null;
try {
o = Class.forName(className).newInstance();
} catch (InstantiationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
instanceList.add(o);
}
ExecutorService executor = Executors.newSingleThreadExecutor();
Iterator<Object> iter = instanceList.iterator();
while (iter.hasNext()) {
Object o = iter.next();
Method m = null;
try {
m = o.getClass().getDeclaredMethod(methodName, new Class[] {});
} catch (SecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchMethodException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Task t = new Task(o,m,new Object[]{});
Future<String> fut = executor.submit(t);
try {
fut.get(2,TimeUnit.SECONDS);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
executor.shutdown();
}
}
public class TestClass1 {
public void execute() {
System.out.println("In class 1");
}
}
public class TestClass2 {
public void execute() {
System.out.println("In class 2");
boolean b = true;
while (b) {
}
}
}
public class TestClass3 {
public void execute() {
System.out.println("In class 3");
}
}